In the design of switching-regulated DC-to-DC converters, choke input filters are required for all outputs. In the case where high voltage outputs are required, large values of choke are required and this poses a design problem in such circuits.
One previous way of providing the required choke was to place such choke input filters between the output transformer and full wave rectifier of such a converter and the output terminal.
The output voltage of the converter is then fed back with a reference voltage through an error amplifier and a regulator loop filter to the control terminal of a pulse-width modulated driver circuit which controls first and second switching transistors which together drive an output transformer by means of an input power source such as a battery. This known type of DC-to-DC converter has a switching transistor duty cycle of from 0 to 50%, i.e., the switching transistors are alternately actuated and no overlap or simultaneous conduction of the switching transistors is utilized.
It is an object of the present invention to provide a switching-regulated DC-to-DC converter circuit in which the switching transistor duty cycle can exceed 50%.
Still another object of the present invention is to provide a new and novel switching-regulated DC-to-DC converter circuit having an input choke interconnected with the input power source, switching transistors and the output transformer, on the input side of the output transformer, and not requiring choke-input filters on each of the outputs.
Yet another object of the present invention is to provide a new and novel switching-regulated DC-to-DC converter circuit having an enhanced range of regulation.
These and other objects of the present invention will become more fully apparent with reference to the following specification and drawings which relate to a preferred embodiment of the invention.